The present inventive concept herein relates to thermal conductivity and a method of measuring the thermal conductivity.
A thermoelectric device includes a thermoelectric generator device converting a thermal energy into an electrical energy and a thermoelectric cooling device converting an electrical energy into a thermal energy. The thermoelectric generator device can reuse a waste thermal energy and thereby it is used in various fields of a vehicle, a spacecraft, a semiconductor circuit, etc.
As standards of thermoelectric performance of the thermoelectric device, a figure of merit (hereinafter, it is referred to as ZT) is used. To develop a thermoelectric device having superior thermoelectric performance, a material having a high ZT has to be developed. However, since variables determining ZT has correlation, it is difficult to develop the thermoelectric device having superior thermoelectric performance only by using a simple bulk material. Thus, recently, a thin film, a nano wire material, etc. using a nano-based technology are being studied.
As a nano-based technology is applied, the importance of method of measuring thermal conductivity and thermal conductance has increased. Since temperature changes of both sides of nano-based materials are minute as compared with a conventional bulk material, it is difficult to measure thermal conductivity and thermal conductance of the nano-based material.